<!DOCTYPE html>
<html>
<head>
  <title></title>
</head>
<body>
<div id="app">
  <h1>{{ title }}</h1>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue@2.5.16/dist/vue.js"></script>
<script type="text/javascript">
  var vm = new Vue({
    el: '#app', // mount到DOM上
    data () {
      return {
        title: 'Hello World'
      }
    }
  })
</script>
</body>
</html>